Magnetic iron product.



TRYGVE D. YENSEN, OF SWISSVALE, PENNSYLVANIA.

MAGNETIC IRON PRODUCT. I

No Drawing.

To all whom it may concern:

Be it known that I, TRYGVE D. YENsEN, a citizen of the United States, Swissvale, county of Allegheny, State of Pennsylvania, (whose post-oilice address is 2113 Delaware Ave, Swissvale, Pennsylvania,) have invented certain new and useful Improvements in Magnetic Iron Products, of which the following is a specification. Y

The present invention relates to iron products having unusual magnetic properties, particularly at high flux densities.

Until a few years ago, pure iron was supposed to have a higher saturation intensity of magnetization than any other material, or in other words, to be the most magnetic material in. existence. lVeiss showed that cobalt when alloyed with iron will make the latter even more magnetic than in'the pure state.

netization which approaches the limit I,,

When the material is. saturated.)

While thus the alloy Fe Co has very desirable characteristics, the cost of cobalt' makes the alloy very expensive. By my present invention, I approach the desirable characteristics of the iron-cobalt alloys by means of a substantially pure iron, havingthe additional advantages over theironcobalt alloys of being. much more easily Worked.

My earlier application for Letters Patent, Serial No. 82340, relates to iron and iron alloys having unusual magnetic properties, my preferred method comprising vacuum fusion in connection With subsequent annealing at temperatures between 900 and 1100' C. For this purpose the product may or may not be pure iron.

The present invention concerns itself more particularly With unusual magnetic properties at exceedingly high inductions and relates only to substantially pure iron. The products may or may not have unusual mag -netic properties at low and medium densities.

Specification of Letters Patent.

residing at In 1912, however, 'f

Weiss found that the alloy corresponding to the compo- .the iron,

Patented Sept. 3, 1918.,

Application filed June 11, 1917. Serial No. 173,971.

1 The products may take the form of roll- To'obtain my improved products, I make use of a low carbon lIOl'l in which phosphorus, sulfur and manganese have, by Well known-methods, been reduced to a-low figure, preferably to 0.05 per cent. or less, when taken in the aggregate, and containmg no appreciable amounts of other elements that can not be eliminated by the subsequent treatment. In my preferred process the iron is further refined by subjecting it, in the molten state, to the action of a vacuum in any suitable manner. The iron may, for example, be melted in a vacuum urnace, or it may be melted under atmospheric .pressure and then transferred to a vacuum tank, where suitable means are provided for retaining it in the molten state during the subsequent refining process.

his process is to be carried on at such a high temperature. at such a pressure, and for such a length of time (from to 2 hours, at an absolute pressure of not more than 5 cm. of n'iercury, and at a bath'temperature of at least 1550 C.) that the gases Will be substantially eliminated from the bath,- and furthermore, that the carbon content of the finishedproduct will be not more than'0.05 per cent.: For the best results the carbon content should not be more than 0.01 per cent. The addition of some iron oxid may be necessary for the elimination of the carbon.

After the elimination of the carbon and the gases, the ,iron is to be further deoXidized, if necessary, to such an extent that the oxygen content of the finished product is' 0.05 per cent., or preferably less. The deoxidizing agent used should be of such a character as to accomplish the deoxidation ithout leaving any appreciable residue in the iron itself or without alloying with the lI'OIl. satisfactorily for this purpose as it does not begin to alloy with the iron until the iron is practically free from oxid.

No alloying elements should be added to as the purpose of the inventionis to obtain a product containing as much pure iron as possible per unit volume, and containing at least 99.70 per cent. Fe.

The refined inn should be allowed to solidify under such conditions as not to be Aluminum may be employed very eontamiiuited by ases or other impurities. Allowing it to solidify in "vacuo may be necessary tor the best results. Finally, any subsequent treatn'ient, whether mechanical or heat treatment, should be done in such a way as to leave the iron practically un-' contaminated.

ay" the hereindescribed process, it is possible to obtain iron with a saturation intensity of magnetization. L, considerably in excess of 1,750, the value for the best grades of iron heretofore known and even exceeding 1800 The Isthmus method may alsobe employed.

Having thusdescribed my invention, What I claim as new and desire to secure by Letters Patent is: y

1. An iron product, containing at least 9970 per cent. iron, characterized by a saturation intensity of magnetization, L, of 1750 to 1 50.

ZJAn iron product, containing at least 99.70per cent. iron, substantially degasified,

characterized by a saturation intensity of magnetization, L, of 1750 to 1850. v

An iron product containing at least 99.70 per centliron, characterized by a saturation intensity of magnetization, 1 of 1800 to 1850. v

4. An iron product containing not over 0.05 per cent. carbon, in which manganese, phosphorus and sulfur have been reduced to 0.05 per cent. or less, when taken in the aggregate, and oxygen to 0.05 per cent. or less, and containing at least 99.70 per cent. iron, characterized by a saturation intensity of magnetization, i of 1800 to 1850.

TRYG-VE D. YENSEN. 

